GM is going through a transformation that may or may not pan out. Meanwhile, if you have particular skills and GM is willing to compensate you justly for those skills - and so long as you are afforded opportunities to enhance your skill set or find satisfaction in some other esoteric fashion at the company... why not stay?
Employment is a roll of the dice no matter who you work for. Read the table as best you can and be mentally prepared for being up and down.